685911601 has 4 divisors (see below), whose sum is σ = 685970932. Its totient is φ = 685852272.

The previous prime is 685911557. The next prime is 685911607. The reversal of 685911601 is 106119586.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 29322225 + 656589376 = 5415^2 + 25624^2 .

It is a cyclic number.

It is not a de Polignac number, because 685911601 - 2¹³ = 685903409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685911607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6066 + ... + 37531.

It is an arithmetic number, because the mean of its divisors is an integer number (171492733).

Almost surely, 2^685911601 is an apocalyptic number.

It is an amenable number.

685911601 is a deficient number, since it is larger than the sum of its proper divisors (59331).

685911601 is a wasteful number, since it uses less digits than its factorization.

685911601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59330.

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 685911601 is about 26189.9141082975. The cubic root of 685911601 is about 881.9068503872.

The spelling of 685911601 in words is "six hundred eighty-five million, nine hundred eleven thousand, six hundred one".